CHINA CLAYS. 119 



CHINA CLAY. 



FROM DYKE'S ORE BANK, ROCK RUN, CHEROKEE CO. 



(NO. A. S.) 



A white, soft, gritty clay, which slakes easily in water. 



The clay requires the addition of 30 per cent, of water 

 to make a workable mass, which is quite lean. Brick- 

 lets made from this shrunk 4 per cent, in drying and an 

 additional 12 per cent, in burning, making a total 

 shrinkage of 16 per cent. 



The tensile strength of the air dried briquettes is low, 

 being only 9 Ibs. per square inch on the average, with a 

 maximum of 12 Ibs. per square inch. 



Incipient fusion occurs at 2000 degrees, F. The clay 

 burns to a hard, marble like, dense body with a very 

 faint bluish tinge at 2100 degrees F. 



The analysis of the clay is as given below. 



Analysis of China Clay, RocTc Run, Cherokee Co. (No. A. 8.) 



Silica 60.50 



Alumina 2C55 



Water 7.20 



Ferric oxide 30 



Lime 90 



Magnesia 65 



Alkalies 2.70 



Moisture .70 



99.50 



Total fluxes 4.55 



Specific gravity 2.52 



The rational composition is 



Clay substance 70.30 



Quartz 18.00 



Feldspar ."7 22.20 



100.50 



